One, a pilot project to prevent cholera, is already under way. The other, aimed at five childhood diseases, is set to begin later this week against .

The wider campaign aims to vaccinate 211,000 infants across the country with a five-in-one vaccine against diphtheria, tetanus, whooping cough, hepatitis B and Hib (Haemophilus influenzae type B, a cause of bacterial meningitis). Children will also get vaccinated against polio and rubella.

Sebelius's personal support of the cholera campaign is surprising, since U.S. health officials have been cool to that pilot project behind the scenes.

According to Haitian health workers, American officials have expressed skepticism about the plan vaccinate 100,000 Haitians against cholera. They say U.S. officials have viewed the cholera vaccination pilot project as a distraction, and have urged Haitians to focus instead on cleaning up their water supply, providing decent sanitation, urging people to wash their hands faithfully, and treating cholera.

But today Sebelius will visit GHESKIO, a Port-au-Prince health center that is vaccinating 50,000 slum-dwellers against cholera. The rural arm, involving an equal number, is being organized by the U.S.-based group Partners in Health.

An HHS spokesman says Sebelius will address cholera vaccination during her visit.

Last month, the country director in Haiti for the U.S. Centers for Disease Control and Prevention told NPR that the CDC has not "been negative" about the cholera vaccine project.

"I'm not aware of skepticism at CDC" over cholera vaccination, Dr. John Vertefueille tells Shots. "At certain points in time we've indicated — and we continue to indicate — that our primary focus is on prevention activities by improvements of water, sanitation, hygiene and good clinical activities" against cholera.

The position the U.S. takes on the issue matters. If the current cholera vaccination campaign succeeds — that is, if Haitians accept the vaccine, and if its organizers show they can deliver the required two doses over two weeks — it would open a larger debate about whether vaccination should be expanded to millions of Haitians at high risk of cholera.

Also, the Haitian government depends heavily on U.S. aid, and the CDC holds considerable sway over Haitian public health policy. Dozens of CDC staffers are stationed at the U.S. embassy in Port-au-Prince.

Meanwhile, the larger vaccination campaign against a slew of childhood diseases is no pilot project. It's the first step in an ongoing campaign that aims to vaccinate every Haitian infant against seven deadly diseases at first. But beginning next year, the campaign will be expanded to the two leading child-killers: diarrheal disease caused by rotavirus and pneumococcal pneumonia.

"It's going to be a huge undertaking," says Dagfinn Hoybraten, chairman of GAVI, the Global Alliance for Vaccine and Immunization, a leading nongovernmental agency promoting vaccination.

"It's a remarkable achievement in public health just two years after the earthquake," Hoybraten tells Shots. "It's a marker of the government's commitment."

GAVI is paying for 80 percent of the pentavalent vaccine campaign, which will cost almost $9 per child. The CDC is picking up the other 20 percent. Over the next three years GAVI will spend more than $9 million on the Haitian vaccination effort.

The logistics are formidable. The pentavalent vaccine requires infants to get injections at six weeks, 10 weeks and 14 weeks. The vaccine must be kept chilled, which requires a complicated infrastructure.

Haiti has had a dismal record in childhood vaccination. "We know that only 50 percent of children have received their complete immunization coverage. This is awful," said Dr. Jean William Pape, director of GHESKIO. (The French acronym reflects the group's origins in the fight against HIV.)

Pape has been battling against the fear that the cholera vaccination project will interfere with the larger childhood vaccination campaign.

To avoid that possibility, Pape had hoped to finish the cholera project before the other one began, but bureaucratic delays have pushed them on top of one another. Since the cholera and polio vaccines can't be given at the same time, it means that children under 10 who are getting the cholera vaccine will not get polio vaccine now. That will require GHESKIO and Partners in Health to track down those children later to protect them against polio.

In the long run, Pape says the vaccination campaigns will be synergistic. "Every effort we make to give one vaccine will make it easier to give the others," he says. "We're learning how to deliver the merchandise better."

So far GAVI has not supported cholera vaccination anywhere. But that could change. Hoybraten says the last time the GAVI board discussed it, the cheaper and easier-to-administer cholera vaccine had not been approved by the World Health Organization. Now it is.

Copyright 2012 National Public Radio. To see more, visit http://www.npr.org/.